The List of tallest buildings in the United States Wikipedia article contains a table that “ranks completed and topped-out buildings in the United States that stand at least 800 feet (244 m) tall, based on standard height measurement which includes spires and architectural details, but excludes antenna masts.”
There are 79 buildings on this list, but two are removed here since no geocoordinates are given (the NEMA Chicago building’s location is just “Chicago,” and the Rainier Square Tower is just “Seattle”).
The USGS Elevation Point Query Service provides elevations for geocoordinates in the United States.
The R package htmltab is used to scrape the Wikipedia table, which contains building height and geocoordinate, and the elevatr package is used to query the USGS service for the elevations of these geocoordinates
The elevation for One World Trade Center is -3.7 m according to this USGS service. It is manually set to zero for display here.